#include "OpenGLRenderer.h"

void OpenGLRenderer::initGL()
{
    //TODO: Wrap these with toggle functions in the base renderer class eventually
    //      Or could just have this as a more specific type of renderer, say OpenGL2DRenderer
    //glShadeModel(GL_SMOOTH);							// Enable Smooth Shading
	glClearColor(0.0f, 0.0f, 0.0f, 0.5f);				// Black Background
	//glClearDepth(1.0f);									// Depth Buffer Setup
	//glEnable(GL_DEPTH_TEST);							// Enables Depth Testing
	glDepthFunc(GL_LEQUAL);								// The Type Of Depth Testing To Do
	//glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);	// Really Nice Perspective Calculations
	glEnable(GL_BLEND);									//Enable alpha blending
    //glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);	//Configure alpha blending
    glBlendFunc(GL_SRC_ALPHA, GL_ONE);	//Configure alpha blending
	//glEnable2D(); 										//Set to 2D drawing
	//glFrustum(-1.0, 1.0, -1.0, 1.0, 1, 100);

	//For textures
	//glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
	glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
	//glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_BLEND);
    glEnable(GL_TEXTURE_2D);
}

void OpenGLRenderer::init(String sTitle, int iWidth, int iHeight, int iBitsPerPixel, bool bFullscreen)
{
    
    //Creates an OpenGL window
    
    GLuint		PixelFormat;			// Holds The Results After Searching For A Match
	WNDCLASS	wc;						// Windows Class Structure
	DWORD		dwExStyle;				// Window Extended Style
	DWORD		dwStyle;				// Window Style
	RECT		WindowRect;				// Grabs Rectangle Upper Left / Lower Right Values
	WindowRect.left=(long)0;			// Set Left Value To 0
	WindowRect.right=(long)iWidth;		// Set Right Value To Requested Width
	WindowRect.top=(long)0;				// Set Top Value To 0
	WindowRect.bottom=(long)iHeight;		// Set Bottom Value To Requested Height

	hInstance			= GetModuleHandle(NULL);				// Grab An Instance For Our Window
	wc.style			= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;	// Redraw On Size, And Own DC For Window.
	wc.lpfnWndProc		= (WNDPROC) WndProc;		// WndProc Handles Messages
	wc.cbClsExtra		= 0;									// No Extra Window Data
	wc.cbWndExtra		= 0;									// No Extra Window Data
	wc.hInstance		= m_hInstance;							// Set The Instance
	wc.hIcon			= LoadIcon(NULL, IDI_WINLOGO);			// Load The Default Icon
	wc.hCursor			= LoadCursor(NULL, IDC_ARROW);			// Load The Arrow Pointer
	wc.hbrBackground	= NULL;									// No Background Required For GL
	wc.lpszMenuName		= NULL;									// We Don't Want A Menu
	wc.lpszClassName	= "OpenGL";								// Set The Class Name

	if (!RegisterClass(&wc))									// Attempt To Register The Window Class
	{
		MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;											// Return FALSE
	}

	if (bFullscreen)												// Attempt Fullscreen Mode?
	{
		DEVMODE dmScreenSettings;								// Device Mode
		memset(&dmScreenSettings,0,sizeof(dmScreenSettings));	// Makes Sure Memory's Cleared
		dmScreenSettings.dmSize=sizeof(dmScreenSettings);		// Size Of The Devmode Structure
		dmScreenSettings.dmPelsWidth	= iWidth;				// Selected Screen Width
		dmScreenSettings.dmPelsHeight	= iHeight;				// Selected Screen Height
		dmScreenSettings.dmBitsPerPel	= iBitsPerPixel;		// Selected Bits Per Pixel
		dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;

		// Try To Set Selected Mode And Get Results.  NOTE: CDS_FULLSCREEN Gets Rid Of Start Bar.
		if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL)
		{
			// If The Mode Fails, Offer Two Options.  Quit Or Use Windowed Mode.
			if (MessageBox(NULL,"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?","NeHe GL",MB_YESNO|MB_ICONEXCLAMATION)==IDYES)
			{
				bFullscreen=FALSE;		// Windowed Mode Selected.  Fullscreen = FALSE
			}
			else
			{
				// Pop Up A Message Box Letting User Know The Program Is Closing.
				MessageBox(NULL,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP);
				return FALSE;									// Return FALSE
			}
		}
	}

	if (bFullscreen)												// Are We Still In Fullscreen Mode?
	{
		dwExStyle=WS_EX_APPWINDOW;								// Window Extended Style
		dwStyle=WS_POPUP;										// Windows Style
		ShowCursor(FALSE);										// Hide Mouse Pointer
	}
	else
	{
	 	//Make the window borderless
	 	dwExStyle=WS_EX_APPWINDOW;								// Window Extended Style
		dwStyle=WS_POPUP;
		
		//dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;			// Window Extended Style
		//dwStyle=WS_OVERLAPPEDWINDOW;							// Windows Style
	}

	AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);		// Adjust Window To True Requested Size

	// Create The Window
	if (!(m_hWnd=CreateWindowEx(	dwExStyle,							// Extended Style For The Window
								"OpenGL",							// Class Name
								sTitle.c_str(),								// Window Title
								dwStyle |							// Defined Window Style
								WS_CLIPSIBLINGS |					// Required Window Style
								WS_CLIPCHILDREN,					// Required Window Style
								0, 0,								// Window Position
								WindowRect.right-WindowRect.left,	// Calculate Window Width
								WindowRect.bottom-WindowRect.top,	// Calculate Window Height
								NULL,								// No Parent Window
								NULL,								// No Menu
								m_hInstance,							// Instance
								NULL)))								// Dont Pass Anything To WM_CREATE
	{
		KillWindow();								// Reset The Display
		MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE
	}

	static	PIXELFORMATDESCRIPTOR pfd=				// pfd Tells Windows How We Want Things To Be
	{
		sizeof(PIXELFORMATDESCRIPTOR),				// Size Of This Pixel Format Descriptor
		1,											// Version Number
		PFD_DRAW_TO_WINDOW |						// Format Must Support Window
		PFD_SUPPORT_OPENGL |						// Format Must Support OpenGL
		PFD_DOUBLEBUFFER,							// Must Support Double Buffering
		PFD_TYPE_RGBA,								// Request An RGBA Format
		iBitsPerPixel,										// Select Our Color Depth
		0, 0, 0, 0, 0, 0,							// Color Bits Ignored
		0,											// No Alpha Buffer
		0,											// Shift Bit Ignored
		0,											// No Accumulation Buffer
		0, 0, 0, 0,									// Accumulation Bits Ignored
		16,											// 16Bit Z-Buffer (Depth Buffer)
		0,											// No Stencil Buffer
		0,											// No Auxiliary Buffer
		PFD_MAIN_PLANE,								// Main Drawing Layer
		0,											// Reserved
		0, 0, 0										// Layer Masks Ignored
	};

	if (!(m_hDC=GetDC(m_hWnd)))							// Did We Get A Device Context?
	{
		KillWindow();								// Reset The Display
		MessageBox(NULL,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE
	}

	if (!(PixelFormat=ChoosePixelFormat(m_hDC,&pfd)))	// Did Windows Find A Matching Pixel Format?
	{
		KillWindow();								// Reset The Display
		MessageBox(NULL,"Can't Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE
	}

	if(!SetPixelFormat(m_hDC,PixelFormat,&pfd))		// Are We Able To Set The Pixel Format?
	{
		KillWindow();								// Reset The Display
		MessageBox(NULL,"Can't Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE
	}

	if (!(hRC=wglCreateContext(m_hDC)))				// Are We Able To Get A Rendering Context?
	{
		KillWindow();								// Reset The Display
		MessageBox(NULL,"Can't Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE
	}

	if(!wglMakeCurrent(m_hDC,m_hRC))					// Try To Activate The Rendering Context
	{
		KillWindow();								// Reset The Display
		MessageBox(NULL,"Can't Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE
	}
    
	ShowWindow(m_hWnd,SW_SHOW);						// Show The Window
	SetForegroundWindow(m_hWnd);						// Slightly Higher Priority
	SetFocus(m_hWnd);									// Sets Keyboard Focus To The Window
	
    this->resize(iWidth, iHeight);					// Set Up Our Perspective GL Screen
    
	if ( !this->initGL() )									// Initialize Our Newly Created GL Window
	{
		KillWindow();								// Reset The Display
		MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE
    }
    
    //Store value
    m_bFullscreen = bFullscreen;
    
	return TRUE;									// Success
}

void OpenGLRenderer::resize(int iWidth, int iHeight)
{
    if (Height==0)										// Prevent A Divide By Zero By
		Height=1;										// Making Height Equal One
    
	glViewport(0,0,Width,Height);						// Reset The Current Viewport
    
	//Save the new width and height
	m_iWidth = iWidth;
	m_iHeight = iHeight;
    
	glMatrixMode(GL_PROJECTION);						// Select The Projection Matrix
	glLoadIdentity();									// Reset The Projection Matrix
    
	// Calculate The Aspect Ratio Of The Window
	//gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);
    
	//int w2 = width / 2;
	//int h2 = height / 2;
    
	//glOrtho(0,width,0,height,-1.0f,1.0f);					//Set up an orthogonal view with 0, 0 at top left and units of exact pixels
    
	glMatrixMode(GL_MODELVIEW);							// Select The Modelview Matrix
	glLoadIdentity();									// Reset The Modelview Matrix
}

void OpenGLRenderer::killWindow()
{
    if (m_bFullscreen)										// Are We In Fullscreen Mode?
	{
		ChangeDisplaySettings(NULL,0);					// If So Switch Back To The Desktop
		ShowCursor(TRUE);								// Show Mouse Pointer
	}

	if (m_hRC)											// Do We Have A Rendering Context?
	{
		if (!wglMakeCurrent(NULL,NULL))					// Are We Able To Release The DC And RC Contexts?
		{
			MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		}

		if (!wglDeleteContext(m_hRC))						// Are We Able To Delete The RC?
		{
			MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		}
		m_hRC=NULL;										// Set RC To NULL
	}

	if (m_hDC && !ReleaseDC(m_hWnd,m_hDC))					// Are We Able To Release The DC
	{
		MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		m_hDC=NULL;										// Set DC To NULL
	}

	if (m_hWnd && !DestroyWindow(m_hWnd))					// Are We Able To Destroy The Window?
	{
		MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		m_hWnd=NULL;										// Set hWnd To NULL
	}

	if (!UnregisterClass("OpenGL",m_hInstance))			// Are We Able To Unregister Class
	{
		MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		m_hInstance=NULL;									// Set hInstance To NULL
	}
}

void OpenGLRenderer::update()
{
    //Check for OpenGL errors
	int r = glGetError();
	if (r != GL_NO_ERROR) { std::cout << "OpenGL Error " << r << std::endl; }
    
    //Now handle window messages
    MSG msg;
    if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))	// Is There A Message Waiting?
	{
		if (msg.message==WM_QUIT)				// Have We Received A Quit Message?
		{
			setQuit(TRUE);							// If So done=TRUE
		}
		else									// If Not, Deal With Window Messages
		{
		 	//Pass the message to the gui
			//GUI.ProcessMessage(msg);
			
			TranslateMessage(&msg);				// Translate The Message
			DispatchMessage(&msg);				// Dispatch The Message
		}
		
		return true;

	}
    return false;
}

void OpenGLRenderer::drawScene()
{
	//glClear(GL_ACCUM_BUFFER_BIT);
	//glAccum(GL_ACCUM, 0.5);
	//glAccum(GL_RETURN, 1); //Multiplies the accumulation buffer by value and copies the result to the backbuffer
	
	SwapBuffers(hDC);		// Swap Buffers (Double Buffering)
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	// Clear Screen And Depth Buffer
	//glAccum(GL_MULT, n);
	glLoadIdentity();									// Reset The Current Modelview Matrix
	//glScalef(1.0, 1.0, 1.0);
	
	return TRUE;										// Everything Went OK
}
